International Publication Number WO 2008/036247 describes a series of compounds which are indicated as having inhibitory activity against aspartic proteases, particularly renin, and which are indicated as being useful in the treatment of aspartic protease mediated disorders. Methyl 2-((R)-(3-chlorophenyl)((R)-1-((S)-2-(methylamino)-3-((R)-tetrahydro-2H-pyran-3-yl)propylcarbamoyl)piperidin-3-yl)methoxy)ethylcarbamate, structurally represented by Formula I,
is one of the compounds disclosed in WO 2008/036247. WO 2008/036247 further discloses the pamoate salt (2:1) of the compound represented by structural formula (I), and describes the use of the trifluoroacetic acid salt for isolation purposes but not for crystallization.
Although the 2:1 pamoate salt of the compound represented by structural formula (I) was obtained in good yield and was highly crystalline, the desired bioavailability and water solubility was not achieved.
There is a need for salt forms of the compound represented by structural formula (I) that are crystalline, have good aqueous solubility, good in vivo oral bioavailability, and otherwise have physical properties that are amenable to large scale manufacture.